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Storm Water Drainage Calculator

Estimate peak stormwater runoff and determine the minimum pipe diameter needed to handle it. Used by civil engineers and drainage designers when sizing pipes for subdivisions, roads, or urban catchments.

Catchment Area (hectares)

Design Rainfall Intensity (mm/hr)

Runoff Coefficient

Pipe Slope (%)

Manning's Roughness Coefficient

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Civil

Structural Beam Load Calculator

Estimate the load-bearing stiffness of a simply supported structural beam based on its span, cross-section, and material. Use this when sizing floor joists, headers, or steel beams for construction projects.

Beam Length (ft)

Moment of Inertia (in⁴)

Elastic Modulus (psi)

Support Type

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Key differences

	Storm Water Drainage Calculator	Structural Beam Load Calculator
Category	Civil	Civil
Inputs required	5	4
Result	Required Pipe Diameter (mm)	Maximum Uniform Load (lbs/ft)
What it does	Estimate peak stormwater runoff and determine the minimum pipe diameter needed to handle it. Used by civil engineers and drainage designers when sizing pipes for subdivisions, roads, or urban catchments.	Estimate the load-bearing stiffness of a simply supported structural beam based on its span, cross-section, and material. Use this when sizing floor joists, headers, or steel beams for construction projects.